intel/compiler: Add some restrictions to MOV_INDIRECT and BROADCAST

These restrictions effectively already existed due to the way we use
indirect sources but weren't being directly enforced.

Reviewed-by: Iago Toral Quiroga <[email protected]>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/intel/compiler/brw_eu_emit.c b/src/intel/compiler/brw_eu_emit.c
index 4f0be550983..e10b1432b5e 100644
--- a/src/intel/compiler/brw_eu_emit.c
+++ b/src/intel/compiler/brw_eu_emit.c
@@ -3373,6 +3373,8 @@ brw_broadcast(struct brw_codegen *p,
 
    assert(src.file == BRW_GENERAL_REGISTER_FILE &&
           src.address_mode == BRW_ADDRESS_DIRECT);
+   assert(!src.abs && !src.negate);
+   assert(src.type == dst.type);
 
    if ((src.vstride == 0 && (src.hstride == 0 || !align1)) ||
        idx.file == BRW_IMMEDIATE_VALUE) {
@@ -3385,6 +3387,20 @@ brw_broadcast(struct brw_codegen *p,
               (align1 ? stride(suboffset(src, i), 0, 1, 0) :
                stride(suboffset(src, 4 * i), 0, 4, 1)));
    } else {
+      /* From the Haswell PRM section "Register Region Restrictions":
+       *
+       *    "The lower bits of the AddressImmediate must not overflow to
+       *    change the register address.  The lower 5 bits of Address
+       *    Immediate when added to lower 5 bits of address register gives
+       *    the sub-register offset. The upper bits of Address Immediate
+       *    when added to upper bits of address register gives the register
+       *    address. Any overflow from sub-register offset is dropped."
+       *
+       * Fortunately, for broadcast, we never have a sub-register offset so
+       * this isn't an issue.
+       */
+      assert(src.subnr == 0);
+
       if (align1) {
          const struct brw_reg addr =
             retype(brw_address_reg(0), BRW_REGISTER_TYPE_UD);